Method and apparatus for sealing bindings



Dec. 9, 1969 STAATS E AL 3,

METHOD AND APPARATUS FOR SEALING BINDINGS Filed July 30, 1965 2$heets-Sheet 1 %v 4 ATTORNEYS Dec. 9, 1969 H, N. STAATS ETAL 3,483,067

METHOD AND APPARATUS FOR SEALING BINDINGS 2 Sheets-Sheet Filed July 30,1965 ATTORNEES United States Patent "ice US. Cl. 156-580 7 ClaimsABSTRACT OF THE DISCLOSURE Apparatus for welding the plural fingers of aplastic binding element to the backbone of the binding element in asimple manner following the assembly of a multiplicity of sheets ofpaper or the like upon the plastic binding element. A unidirectionallyangularly deflected sealing probe is employed in a manner providingrapid manipulation of the members being bound.

The present invention relates to the field of binding a plurality ofperforated sheets into a booklet or the like by means of a plasticbinding element. MOre particularly, the invention is concerned with theprovision of a substantially more efficient method, binding element, andapparatus for rendering the normally loose-leaf binding element apermanent binding device.

As those familiar with the art of applying thermoplastic plastic bindingelements to a plurality of perforated sheets are aware, it isoccasionally desired that the binding elements be made permanent.Attempts have been made in the past by applying heat to the plasticfingers of the binding. However, whereas prior Welding systems haveproved satisfactory for small numbers of books being bound by hand andunder rather critical temperature controls, to our knowledge no trulyefiicient system has been constructed for rendering a normallyloose-leaf plastic binding element permanently bound on a fast, trulymass-production basis. In accordance with the present invention, a veryrapid, eflicient and relatively non-critical method and apparatus havebeen devised for rendering the typically loose-leaf bound booklet apermanently bound one.

In accordance with the present invention, a plurality of perforatedsheets of paper or the like are bound in a loose-leaf manner by means ofa plastic binding element. This element comprises a thermoplastic curledbinding element composed of a longitudinally extending backbone memberhaving a plurality of transversely extending integral fingers curledinto a generally circular configuration to lap the backbone. Inaccordance with standard practice, such plastic binding elements mayreadily be reopened for the addition or subtraction of perforated sheetsby holding the backbone and pulling the curled fingers away from itsufficiently for the free ends thereof to accept additional sheets. Bythe present invention the free ends of the backbone fingers are weldedby a single operation to adjacent portions of the binding elementbackbone.

In further accord with the invention, this welding operation takes placein a fixture that automatically aligns the perforated sheets and theplastic binding element into a position in which the fingers may readilybe welded to the backbone with utmost accuracy and simplicity, and thatthen permanently welds them as positioned. 1

In order to provide simple and substantially complete repeatability ofpositioning of the book and binding during the sealing operation, thebinding is preferablyconstructed in a novel manner by providing itsbackbone of a predetermied width tailored to the punched apertures ofthe perforated sheets. For example, in co-operation with 3,483,067Patented Dec. 9, 1969 apertured sheets having the inner edge of thepunched aperture approximately A from the outer edge of the sheet, as isconsidered a conventional practice, the width of the backbone would bein the general area to /2". The width of the backbone would be keptsubstantially constant throughout the ordinary range of standard bindingsizes. This is true since the dimension of the backbone is designed forproviding a suitable finger-backbone lapping condition, which conditionis substantially the same independently of the length of the backbonefingers. Additionally, special fixtures are provided that are tailoredto the physical configuration of the binding element to assure properalignment of the components during the actual sealing operation.

In order to still further speed up the actual sealing of the binding,the sealing cycle is reduced to a minimum through the utilization ofwave-form energy, either in the form of ultrasonic waves at a frequencygenerally in the range of 20 kilocycles to kilocycles per second, orwaves at radio frequencies generally in the range of 15 t 60 megacyclesper second. These energy applications are termed, for convenience,ultrasonic sealing and dielectric sealing, respectively. In bothinstances the sealing which occurs at the interface between abuttingsheets of material is accomplished with a minimum of heating at theouter peripheral surface of the material as in most prior heat sealingdevices employing heated electrodes that operate to heat the interfacesolely by conductivity through the plastic binding element itself. Sincethe heating takes place extremely rapidly and substantially at theinterface in the method according to the present invention,substantially smaller quantities of heat are required and, further,substantially no degradation occurs in the plastic surrounding the Weldarea. Accordingly, extremely rapid welding with a high etficiency weld,is provided.

The invention takes several forms. In addition to a novel bindingelement configuration, the methods and apparatus employed in accordancewith the invention embody a ultrasonic or dielectric probe elementhaving longitudinally deflected ends for insertion between thetransverse fingers of a thermoplastic binding element, and fortransverse movement against a back-up bar in a position with thedeflected ends of the probe tightly clamping the overlapping ends of thebinding element fingers to the binding element backbone. Thelongitudinally deflected probes provide absolute accuracy of weldposition and permit automatic shifting of the binding, where desired, inthe process of positioning the binding for the sealing step. Inaccordance with illustrated variations in the form of the apparatusemployed in the method of the present invention, the probes may bevertically downwardly extending for co-operation with a generallyhorizontal, upwardly facing back-up bar or the probes may be generallyvertically upstanding for co-operation with a horizontal, generallydownwardl facing back-up bar. Manipulation of the book being boundvaries with the specific probe and back-up bar arrangement. Acommercially satisfactory sealed binding is, however, the result ofmanipulation of the apparatus in various forms.

It is, accordingly, an object of the present invention to provide anovel binding element.

Another object of the present invention is to provide a novel andsubstantially improved method for heat-sealing a thermoplastic bindingelement.

Still another object of the present invention is to provide an improvedapparatus capable of heat-sealing, by waveform energy application,thermoplastic binding elements.

A feature of the invention is the provision of the longitudinallydeflected heat-sealing probe means for transversely passing the fingersof a thermoplastic binding element while providing for clamping contactbetween the ends of such fingers and the backbone of the bindingelement.

Still a further feature of the invention is the provision of a bindingelement having a backbone of a width on the order of V8" to A2" for usewith perforated sheets having the most remote edges of the perforationsapproximately /4 from the edge of the sheet.

Still a further object of the invention is the provision of anultrasonic heat-sealing method and apparatus for permanently andextremely rapidly sealing loose-leaf binding elements of thethermoplastic type.

Still other and further objects and features of the invention will atonce become apparent to those skilled in the art from a consideration ofthe attached specification and drawings wherein two embodiments of theinvention are shown by way of illustration only, and wherein:

FIGURE 1 is a generally isometric view of an apparatus for theheat-sealing of bound booklets showing a booklet in position forinitiation of the heat-sealing step;

FIGURE 2 is a partial cross-section taken along the line II-II of FIGURE1;

FIGURE 3 is a side-elevational view substantially enlarged, of a portionof the apparatus shown in FIG- URE 1;

FIGURE 4 is an enlarged view generally as illustrated in FIGURE 3wherein the parts are in position for the heat-sealing step;

FIGURE 5 is a modified form book support and probe combination employedin a variation of the method of the present invention; and

FIGURE 6 is a side-elevational view of a modified form of constructionillustrated in FIGURE 5, in the position of the heat-sealing step.

As shown on the drawings:

As may be seen from a consideration of the embodiment illustrated inFIGURES 1 through 4, a booklet is provided having outermost sheets orcovers 10, 11 and a plurality of enclosed sheets 12. These sheets areperforated along one edge thereof with a plurality of perforations 13which accommodate the fingers 14 of a thermoplastic binding elementgenerally indicated at 15. The binding element 15 is provided with abackbone 16 extending longitudinally thereof throughout its entirelength and having integrally secured thereto the multiple fingers 14.

The binding and booklet above described are initially placed upon asupport device generally indicated at 20 at the left-hand end designated21 in FIGURE 1. For sealing, the booklet is pushed to the right-hand endof the device in the direction of arrow 22 and into the position shownat 23 in FIGURE 1. The book is separated to provide the outermost sheetsin a backwardly open condition as shown in FIGURE 2 prior to itsplacement on section 21 of the device 20. This separation of the bookinto the position shown in FIGURE 2 automatically positively positionsthe backbone 16 between the outermost sheets 10 and 11 and, when thebooklet is thus placed upon the support 21 the overlapping ends 14a ofthe fingers 14 are accurately positioned immediately above the backbone16, As thus positioned, the multi-toothed probe 25 having teeth 26 mayreadily pass vertically downwardly past the innermost ends of the boundsheets into clamping contact with the overlapping portions 14a of thefingers 14 and the back-up support 23.

As may be best observed from a consideration of FIG- URES 3 and 4, theteeth 26 of the probe 25 are deflected longitudinally of the axis of theprobe 25 in the manner illustrated at deflected ends 26a. The ends 26aare of a width smaller than the gap between adjacent fingers 14 so thatdownward movement of the probe, in FIG- URE 3, will cause passage of theprobe teeth 26 between adjacent fingers 14 until the beveled surfaces26!) contact the fingers 14. At the time of such contact, the bindingelement, and the sheets bound therein, are axially slid toward the rightas viewed in FIGURE 3 by continued downward movement of the probe 25. Asthe binding moves toward the right, it assumes a condition shown inFIGURE 4 in which the ends 26a of the teeth 26 are in tight contact withthe overlapping ends 14a of fingers 14, clamping them tightly to thebackbone 16 and against the back-up bar or support 23. With the parts inthis position, heat-sealing energy may be supplied to the overlappingportions by way of the teeth 26.

We have found that a particularly advantageous technique of heat-sealingthermoplastic binding elements, for example of the polyvinyl chloridetype, comprises the application of ultrasonic waves. These waves, at thefrequency of approximately 20 kilocycles per second, may be generated byany conventional ultrasonic wave-form generator having a mechanicalvibration output, not forming a part of this invention per se. Theenergy is transmitted by contacting the said output with the clampedbinding by touching the output to the binding directly (not shown), orby employing the back-up bar 23a or the finger probe 25 as the outputmember. It has been found that when energy is applied to the clampedplastic portions, as illustrated, that the heating takes placesubstantially only at the interface area between the overlapping fingersand the backbone of the binding element. This is true since thewave-form energy passes through the plastic until it strikes theinterface at which point the energy is deflected and causes molecularvibration substantially at the interface. This molecular vibrationcauses heat which satisfactorily seals impact modified polyvinylchloride or similar elements of a copolymer of polyvinyl chloride andvinyl acetate binding elements substantially instantaneously. Thesesubstances, as preferably used, have a softening or formabilitytemperature of about F. and are resilient after forming.

In spite of the fact that the plastic used is not a rigid, extremelyhard substance, such as metal, and prior techniques of ultrasonicwave-form application have strongly suggested that soft materials suchas impact modified polyvinyl chloride would not prove heat-scalable, wehave found that such binding elements are very successfully heat-sealedin the manner above described upon the application of ultarsonicwave-form energy to the binding when in clamped condition. In thistechnique, it has been found that a non-metallic back-up member 23 mayreadily be employed since electrical conductivity of the back-up isnon-essential. This is true since the ultrasonic waves appear toaccomplish their heating effect at the interface and the energy may beapplied at one point rather than as a part of a circuit.

As above noted, it is equally possible to provide heatsealing by way ofa dielectric device employing radio frequency vibrations. In such anevent, however, it is preferred that the probe 25 be of electricallyconductive material, properly insulated from all surrounding areas, and,similarly, that the back-up support 23 be provided with an electrode 23aforming a part of the radio frequency wave-form generator. In view ofthe extremely serious losses of energy occasioned by leakage, however,it is preferred that the electrode 23a and the metallic probes 25 beelectrically isolated from all surrounding materials as much aspossible, .and as generally illustrated in FIGURE 2. where the back-upsupport 23 is constructed of dielectric material and the bar 23a iselectrically conductive.

In the method and operation described in connection with the structuresillustrated in FIGURES 1 through 4, a stop 23b is provided forpositioning the backbone 15. This positioning accurately presents thegap between the fingers 14 to the ends 26a of the probe teeth 26. Theteeth are rounded as at 26b to avoid any snagging with the fingers 14and with the backbone positioned as shown in FIGURE 3, downward movementof the probe 25 will automatically shift the binding toward the rightinto the sealing position. Stop 23b thus provides accurate means formanually positioning the booklet in the position shown in FIGURE 1. Inordinarily practicing the method of the present invention, a book wouldbe initially opened into the condition shown in FIGURE 2 and placed uponthe support portion 21 while the probe 25 is sealing a previouslypositioned booklet. Then, as the probe 25 is lifted, the boklet isshifted from area 23 ofr toward the right for reclosing and stackingwhile the booklet then resting upon the portion 21 is shifted to theright into position against the stop 23b. As the probe 25 is energizedinto the downward position, by means of a conventional mechanical press,or the like, the next booklet is opened and positioned on the supportportion 21.

As has been observed above, the backbone 16 is dimensionally importantto the method above described. By providing the backbone on the order ofto /2" wide, it is adequately supported as illustrated in FIGURE 2 andis automatically properly positioned. If the backbone were substantiallygreater in width, inaccurate positioning would be possible or anextremely wide and unsatisfactory support would be required.Alternatively, if the backbone were extremely narrow, substantially noaccuracy whatever would be provided in the positionmg.

In the embodiment of the apparatus illustrated in FIGURES 5 and 6, theprobe, generally indicated at 125, is provided with upstanding teeth 126having longitudinally, or axially, deflected portions 126a. The probe125 has a vertical base portion 124 having rigidly secured thereto ashelf support 124a adjustably mounted upon diagonal brace 124b. Thebrace 1241; is adjustably mounted relative to the base 124 by way of athreaded adjusting nut 124e, permitting angular tilting of the supportshelf 124a. The shelf is vertically adjustable by loosening screws 1247passing through slots 124g in bar 1242. A back-up bar 123 having a rigidbackbone-engaging portion 123a is vertically downwardly movable forclamping engagement with the backborn 16 and lapping finger portions 14aof the fingers 14 of binding element 15.

A plurality of vertically extending stop members 127 are rigidly securedat 128 to the support 124 and have a thickness sufficiently small topermit their passage between the adjacent fingers 14 of the binding 15.As may be seen from a consideration of FIGURE 6, the combination ofsupports related with the stop 127 is such that axial movement of thebooklet in the direction of arrow 129 causes engagement of the leadingor outermost edge 16a with the stops 127 causing the binding tooscillate to a position in which the edge portion 16b of the backbone,between the fingers 14, abuts the top cover sheet 10. At this position,due to the width of the backbone being greater than the distance betweenthe perforations in the sheet 10, the backbone 16 remains projectingbeyond the edges of the booklet in the position illustrated, in anoverlapping relation with the ends 14a of the fingers 14. The back-upbar 123 may then be reciprocated vertically downwardly clamping theportions 16 and 14a upon the upper ends of deflected portions 126a ofthe probe teeth 126. It will be observed, accordingly, in the methodemployed in the welding of bindings on the apparatus of FIGURES 5 and 6,that the positioning of the backbone is again specifically determinedprior to welding by a relationship with the outermost cover sheet of thebooklet or other device being bound. This permits fast and very accuratecomponent positioning, and hence, repeatability of the process.

The apparatus may be used in several manners. However, we have found amost eflicient technique of operation is to provide adjustment of theshelf 124a at a level low enough to support a second booklet shown at12a, beneath the booklet being welded. Where no such booklet is employedin the process, slowing the process down substantially, the shelf may bepositioned immediately under the booklet 12. Employing the arrangementillustrated in FIGURE 6, the bottom booklet 12a is one previouslywelded. With a thus previously welded booklet 12a positioned as inFIGURE 6, the unsealed book 12 is pushed in the direction of arrow 129until edge 16a of the backbone is against the stop 127, at which pointthe booklet is lowered downwardly, moving toward the left as it engagesthe deflected ends of the ends 126a of probe teeth 126 until it reachesthe resting position upon the booklet 12a. In this position the upperends of the teeth 126 are immediately under the ends 14a of the bindingelement fingers 14.

The back-up bar 123 is then vertically moved downwardly clamping thebackbone and fingers, at which point ultrasonic or radio frequencyenergy is applied by any conventional apparatus through the probe orback-up bar. As the back-up bar 123 is moved downwardly by a press orthe like, and the operator is not occupied with actuation of the press,the lower booklet 12a is moved by the operators right hand to a stack ofsealed booklets. As this operation is performed with the right hand theleft hand reaches for an unsealed book, placing the unsealed book abovethe book being sealed. While the operator waits for the completion ofthe welding or sealing, the backbone is manually rolled into approximately the position shown in FIGURE 6. Upon completion of thewelding cycle, both the uppermost unwelded booklet and the then lowerwelded booklet are lifted upwardly and to the right, clearing the weldedbooklet from the teeth 126a, and then lowered into the position shown bybooklet 12a in FIGURE 6. The uppermost booklet is then moved to theright starting a new sequence of motions. It has been found that anoperator can seal previously bound booklets at a very rapid rateemploying the sequential operation methods described in connection withthe illustrated forms of apparatus in FIGURES 1 through 6.

Although no lognitudinal stop has been described in connection withpositioning of the book 12 to be sealed in the arrangement shown inFIGURE 6, it is nevertheless clear that an axial stop at the right-handedge of sup port table 124 may be provided to properly position thebooklet to be sealed so that the deflected portions 126a of the teeth ofthe probe 125 will be immediately under the spaces between fingers 14 atthe time the booklet is initially introduced from above. Downwarddropping of the booklet Will then, of course, cause axially left-handedmovement of the booklet by the deflection action of the portions 126a ofthe teeth 126 until the uppermost portion of the teeth is immediatelyunderneath the ends 14a of the binding element fingers 14.

From a consideration of the above specification and drawings, it will beclear that variations in apparatus and the improved method of sealingpreviously bound booklets, may be made without departing from the scopeof the novel concepts of this invention. It is, accordingly, ourintention that the scope of the invention be limited solely by that ofthe hereinafter appended claim.

We claim as our invention:

1. Apparatus for welding a thermoplastic binding having a longitudinallyextending backbone with a plurality of transversely extending fingerscurled into lapped condition therewith, which comprises a longitudinallyextending backing bar having one surface thereof adapted for back-upsupport of the binding element backbone, probe means having a pluralityof fingers extending toward said backing bar and having the ends thereofadjacent the backing bar angularly unidirectionally deflectedlongitudinally of the axis of the backing bar to permit insertion of theprobe fingers past the backbone fingers in a generally transversedirection and axial positioning of the ends of the probe fingers inalignment with the lapped ends of the backbone fingers for clamping thelapped ends of the backbone fingers to the backbone, and means applyingenergy to the clamped areas to melt and thereby weld the clamped areas.

2. Apparatus for welding a thermoplastic binding having a longitudinallyextending backbone with a plurality of transversely extending fingerscurled into lapped condition therewith, which comprises a longitudinallyextending bcaking bar, one surface thereof adapted for back-up supportof the binding element backbone, an abutment at one end of said backingbar for longitudinally positioning a binding element relative to saidbacking bar, probe means having a plurality of fingers extending towardsaid backing bar and having the ends thereof adjacent the backing barunidirectionally angularly deflected longitudinally of the backing barin a direction toward the abutment, means transversely moving the probemeans toward said backing bar in a position providing initial insertionof the deflected ends of the probe fingers between adjacent fingers ofthe backbone whereby continued transverse movement of the probe meanscauses longitudinal movement of the binding away from the abutment andaxial positioning of the ends of the probe fingers in alignment with thelapped ends of the backbone fingers for clamping the lapped ends of thebackbone fingers to the backbone, and means applying energy to theclamped areas to melt and thereby weld the clamped areas.

3. Apparatus for welding a binding element having a backbone with afinger curled into lapping contact therewith and containing a pluralityof perforated sheets, which comprises a longitudinally extending backingbar having one surface thereof adapted for back-up support of thebinding element backbone, probe means having a plurality of fingersextending toward said backing bar angularly undirectionally deflectedlognitudinally of the backing bar to provide positioning of thedeflected end of the probe in alignment with the lapped end of thebackbone finger for clamping the lapped end of the backbone finger tothe backbone, and means applying waveform energy to the clamped area tomelt and thereby weld the finger to the backbone in the clamped area.

4. The apparatus of claim 3 wherein the back-up bar is positioned belowthe backbone and supports the weight of the backbone during welding.

5. The apparatus of claim 3 wherein said back-up support bar ispositioned above the backbone and wherein meansare provided forsupporting the perforated sheets in a generally horizontal positionduring welding.

6. The apparatus of claim 3 wherein said wave-form energy comprisesultrasonic vibrations on the order of 20,000 cycles per second.

7. The apparatus of claim 3 wherein said Wave-form energy comprisesradio frequency energy in the range of 35 to 45 megacycles.

References Cited UNITED STATES PATENTS 2,106,419 1/1938 Anderson 281-212,202,097 5/ 1940 Farkas 281-21 2,571,525 10/1951 Blitstein 11--12,649,877 8/1953 Renn 156380 3,022,814 2/1962 Bodine 156-73 3,101,6348/1963 Cooper 15673 DOUGLAS J. DRUMMOND, Primary Examiner US. Cl. X.R.156-583

